Wireless signaling system



Dec. 2, 1924. 1,517,654

H. J. ROUND ET AL WIRELESS SIGNALING SYSTEM Original Filed March 30, 1921 2 Sheets-Sheet 1 amvewbo'cs Dec. 1924 11,517,654-

H. J. ROUND ET AL WIRELESS SIGNALING SYSTEM Original Filed March 3 1921 2 Sheets-Sheet 2 Svwenbozs HEN) I FOUND H. MCLELLFN 3513 Gwen m1 (ikvmfli dad/M Patented Dec. 2, 1924 UNITED STATES.

v 1,517,654 PATENT oF Ics.

HENRY OSEPH ROUND, OF LONDON, AND ARCHIBALD MGLELLAN, F SWANSEA, ENG- LAND, ASSIGNORS 'I'O RADIO CORPORATION OF AMERICA, OFQN'EW YORK; N. K, A

conrosnrron or nnLAwAnn.

WIRELESS SIGNALING SYSTEM.

Application filed March 80. 1921, Serial No. 457.152. Renewed April 15, 192%.

To all whom it may camera:

Be it known that we, HENRY JOSEPH ROUND, of 9 Woodberry Crescent, Mu'swell Hill, London, N., England, and ARoHIBALn MolLnLLAn, of 13 Northampton Place,

Swansea, England, both subjects of the King of Great Britain, have invented new and useful Improvements in or Connected'with Wireless Signaling :Systems, oi which the W following is a specification accompanied by drawings,

; When a valve'system consisting of a valve or valves and an oscillating circuit is oscillating, various accidental circumstances may 1513 prevent the aerial from oscillating or may produce a variation in wave length which will be harmful to the valve or valves or 'to the reception of signals.

' The object of our invention is toobviate the possibility of such harm,

The novel features which we believe to be characteristic of our invention are set forth with particularity in the appended claims. lhe invention itself, however, together with further objects and advantages thereof will best be understood by reference to the following description of several arrangements embodying the invention taken in connection with the accompanying drawing in which Fig, l is a diagrammatic view illustrat ing one form of our invention,

Figs; 2, 3 and 4: are diagrammatic views of modifications,

According to one form of ourinventiou,

Ell

eter relay, one coil oi which is in series with the valve, but not including the part of the circuit which feeds power to the aerial and the other in series with a resistance across the valve. The dynamometer will be adjusted so that it the power into the valve exceeds a certain value, the dynamometer re; lay operates a switch or switches for cutting off or reducing the power.

lin accordance with the arrangement of Fig. i of the accompanying drawings, a normal transmittin circuit with the addition ofcoils A and is arranged with mutual ,jinduction between them and so that one is "movable in respect to the other, isthe "current coil" connected between the positive feed main" and "the anode of the valve i7, and l? is the voltage coil connected across thevalve, resistance being suitably adi we introduce into such a system a dynamom justed so as to give sufiicient current through E without absorbing appreciable power. On the moving coil, such as A, is fixed a contact A which controls the feed current by movement into or out of engagement with contact A If the aerial circuit'is all right the energy llowing into the valveshou'ld be fairly constant, but if owing to any cause such as an earthed aerial the energy flow in the oscillation circuit is decreased and that into the valve isjncreased, the main feeding circuit is immediately broken by the movement of the coil which may be caused to operate an alarm in any suitable manner (not shown). If desired the coil A can be placed in the aerial feed and would then be actuateol by a drop in energy; this, however, adds the complication that inter-working with the key circuit has to take place to prevent the circuit openmg when the key'is up In another form shown in Fig. 2 we use a differential relay which works if there is an absence or a reduction of power in the aerial or some circuit coupled with the aerial when the main power is on. This relay is arranged so that as long as the key current or main teed current and aerial current flow,

simultaneously it is not in operation, but it by any chance'aerial current does not how, their a cut out is thrown. As the mean value or the grid current usually depends on. the oscillations of the aerial system this current often be used instead of the aerial current, The differential relay may worl: with direct current obtained from the aerial current and key current by any well known means The relay may by a sluggish hot wire relay and may act so as to cut ofi the power it the aerial current does not flow or is reduced to any predetermined value.

Fig. 2 illustrating this arrangement shows a movable contact C controlled byt-he two hot wire elements T T of a diilerential renot broken. If therefore the aerial does not oscillate or only oscillates to-a weaker extent than normal, the key circuit is broken and so the valve is rotected from damage.

If a condenser D be included, as shown, in the circuit through T then if thecurrents in that circuit drop owing to a change of tune in the aerial,"the key circuit will be broken. I

By a simple development of this scheme we can provide means whereby a variometer can be actuated to restore the tune of an aerial tothe normal should it vary in either sense by a predetermined amount.

This is illustrated in Figure 3 where a plurality of circuits are coupled to the aerial, two circuits E F being tuned one a certain amount above and; the other a certain amount below the aerial and including hot wire elements T, T.

Should the tune of the aerial vary so much that the aerial is in tunewith either E or F, contact 0 is hroughtagainst one or the other of the fixed contacts C C so as to actuate a relay G which controls two solenoids H, H operating a variometer L by which inductance is added to or withdrawn from the aerial so as to restore it to its normal tune, or'at any rate so near that tune that the circuit of relay G is broken.

Obviously the relay G can be arranged in other ways, :for example, to operate the cut out 0 in the feed main of Figure 2, or may cut inductances of definite values in and out of the antenna circuit.

As a modification of the arrangement il lustrated in- Fig. 2 we can employ two relays one of which is normally closed and can be actuated by the aerial current, and the other of which is normally open and actuated by the key current.

if their contacts be arranged in series, these two relays may control a cut out circuit so that unless the aerial current rela immediately opens on closed the cut out Works. x

This is illustrated in Fig. in which the contact D controlled'by the\ ot wire T in the key circuit is normally open and is in series with a relay M and the normally closed contacts E controlled byhot wire T in the circuit coupled to the aerial.

It will be seen that when the key K is pressed, unless suflicient current flows in the aerial to open the contact of T relay M will be energized owing to the closing of its circuit by hot wire T and therefore cut out 0 will be thrown.

Obviously other kinds of relays, such as direct current relays, may be used, in which case the aerial currents will be rectified in any well known manner.

With the arrangement of Fig. A, it will be wise, if T T are fast relays, to make relay M sluggish so that sending will not be unnecessarily interrupted by slight kicks is operated.

2. A wireless signaling system comprising in combination a valve, an oscillation circuit, a relay adapted to be operated when the relative currents through the oscillation circuit and valve are altered and means for controllin the supply of-energy to said valve, said means being adapted to be operated by said relay when the relative currents in said oscillation circuit and valve are altered beyond certain limits.

3. A wireless signaling system comprising in combination a valv'e an oscillation circuit and a relay having a coil in series with the valve and another coil across the valve said coils being relatively movable and adapted to interrupt the supply of ener to the valve when the current through t e valve relative to the current in the oscillation circuit is varied beyond certain limits.

4. A wireless signaling system comprising in combination, a valve, an oscillating circuit and means for automatically interrupting the supply of ener to the valve on the current in the osci latinng circuit falling below a certain value.

, 5. A wireless signaling system comprising in combination, a valve, an oscillating circuit and relay having a coil in series with the valve and another coil in series with a resistance across the valve and adapted by the relative movement of said coils to intery rupt the supply of power to the valve if the key relay being that supply exceeds a certain value.

6. The combination with a vacuum tube oscillator of a source of current for supplying electrical energy thereto, and means for interrupting the supply of current to said oscillator upon the occurrence of abnormal conditions, comprising a relay having two windings supplied with current from two different circuits, said windings being so proportioned that the effects of the two currents normally oppose and neutralize each other and the circuits from which the currents are supplied being so chosen that upon the occurrence of abnormal conditions the effect of one current will overbalance that of the other and cause the relay to operate and interrupt the supply of current to the oscillator.

7. The combination with a vacuum tube oscillator of a source of current for supplying electrical energy thereto, and means for interrupting the supplyof current to said oscillator upon the occurrence of abnormal conditions comprisin a relay having two windings supplied with current from two .difl'erent circuits, one of said circuits being a circuit by means of which current. is supplied to the plate circuits of the vacuum tubes, said windings being so proportioned that the effects of the two currents normally oppose and neutralize each other and the circuits from which the currents are supplied being so chosen that upon the occurrence of abnormal conditions the efiect of one current will overbalance that of the other and causethe relay to operate and in.- terrupt the supply of current to theoscillator. v

8. The combination with a vacuum tube oscillator of a source of current for supplying electrical energy thereto, and means for interrupting the supply of current to said oscillator upon the occurrence of abnormal conditions comprising a relay having two windings supplied with current from two diiferent circuits, one of said circuits being a circuit by means of which current is supplied to t e plate circuits of the vacuum tubes, and the other of said circuits being a circuit in which the current remains substantially constant as long as oscillations are produced, but decreases greatly when oscillations are interrupted by means other than normalkeying, said windings being so proportioned that the effects of the two currents normally oppose and neutralize each 1 other and the circuits from which the currents are supplied being so chosen that upon the occurrence of abnormal conditions the eflect of one current will overbalance that of the other and cause the relay to operate 40 and interrupt the supply of current to the oscillator.

HENRY JOSEPH ROUND.

ARCHIBALD MQLELLAN. 

